split off tickets: also rename the subject
split off tickets: also rename the subject

This makes it more clear in the inbox which ticket is the new one.

https://trello.com/c/IiN0w4kf/1144-brimir-tickets-abspalten
(cherry picked from commit f1742b57c0db16e74faac069c0bea77a0aa516a1)

fiedl/brimir,ivaldi/brimir,ivaldi/brimir,fiedl/brimir,fiedl/brimir,ivaldi/brimir,fiedl/brimir,ivaldi/brimir